The present invention relates to a gas turbine and more particularly, to a gas turbine which injects water droplets into an intake air of a compressor of the gas turbine.
A conventional gas turbine is caused to drop its output in a summer season when the temperature increases, therefore, various arrangements have been proposed as a method to recover the dropped output.
JP-A Laid-Open No. 7-97933, JU No.61-37794, or JP-A Laid-Open No. 5-195809 disclose that the intake air of the compressor is cooled.
Further, JP-A Laid-Open No. 61-2837323 disclose that water is supplied from the inlet of the compressor and from the intermediate stage of the compressor in a combined system of a gassification furnace and a gas turbine.
Further, JU-A No. 56-43433 discloses that a supply port through which to supply water droplets is provided in its compressor, and JP-A No. 2-211331 discloses a gas turbine which is provided with two types of compressors of a high pressure and a low pressure, and an intermediate cooler which is provided between these two types of compressors. Still further, JP-A No. 6-10702 discloses a technique to inject water into an intermediate section between an upper-stream compressor stage and a down-stream compressor stage in a compressor group having a plurality of compressor stages in order to reduce power consumption.
However, what are disclosed by these related arts of JP-A No. 7-97933, JU No. 61-37794 or JP-A No. 5-195809 are addressed simply to dropping temperatures of intake air to be admitted into the compressor so as to be able to improve its output. JP-A No. 61-283723 merely discloses vaporization of water droplets in the compressor and utilization thereof as a medium to cool the turbine blades, and as a consequence, improvement of turbine cycle characteristics.
Further, JP-A No. 2-211331 discloses the gas turbine which is provided with an intermediate cooler which is provided between the two types of compressors of high pressure and low pressure, and wherein means for detecting a temperature and a humidity at the inlet of the high pressure compressor are provided, and a feed water flow to the intermediate cooler is controlled. However, this control does not teach nor suggest water injection into the compressor itself, and is not concerned with control of humidity at the inlet of the compressor.
In consideration of an actual operation of a gas turbine or a combined cycle using a gas turbine and a steam turbine, there is required a development of a system which can realize a safety operation of the gas turbine while always ensuring protection of the gas turbine itself, and which can improve its output and thermal efficiency using a simple arrangement.
An object of the invention is to provide a gas turbine which can realize improvements both on its output and thermal efficiency through injection of liquid droplets into intake air introduced to the inlet of the compressor using simple facilities suitable for actual application, and also a safety operating system using the same.
A first present invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged at an up stream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, a detection unit for detecting the humidity of air to be supplied to the compressor, and a controlling unit for controlling a quantity of water droplets to be sprayed from the injection unit on the basis of a signal from the detection unit.
For example, it is possible to control a spray quantity of the liquid droplets according to the detected signal.
The humidity of intake air at the upstream side of the injection unit, for example, is detected and a spray quantity of the liquid droplets is controlled to be more when the humidity is low than when it is high.
Further, it is preferable for the control unit to have a detection unit for detecting the temperature and humidity of air supplied to the compressor and control a spray quantity of water droplets sprayed from the injection unit on the basis of the detection signal. By detecting the temperature of air at the upstream side of the injection unit, the spray quantity of water droplets is controlled to be more at a lower temperature than at a higher temperature, and the spray quantity of water droplets is controlled to be more when the humidity of air at the upstream side of the injection unit is lower than when the humidity is higher than when low.
Further, it is possible to control the above-mentioned spray quantity on the basis of output, etc. and use it as a limit value of the spray quantity on the basis of the above-mentioned detection signal. The control unit has a limit value set for a spray quantity of water droplets from the injection unit on the basis of the detection signal and controls the spray quantity to be within the above-mentioned limit value.
For example, a spray quantity of water droplets is determined according to output. In this case, the temperature of intake air at the upstream side of the injection unit is detected, the above-mentioned limit value is made higher when the temperature is lower than when high, the above-mentioned limit value is made higher when the humidity of intake air at the upstream of the injection unit is lower than when high, and a spray quantity of the water droplets is controlled (corrected) not to exceed the limit value.
Thereby, the soundness of the compressor is secured and a high output operation of the gas turbine can be executed. Since a water spray quantity is adjusted by considering the humidity of intake air when water droplets are injected into the intake air, a quantity of water droplets introduced into the compressor without evaporating until the injected water droplets reach the compressor inlet can be controlled to be a proper quantity, and a quantity of water droplets having been evaporated until they reach the compressor inlet and a quantity of water droplets having been evaporated within the compressor can be suitably controlled. Therefore, the gas turbine can be operated at a high output while securing the soundness of the plant, taking into consideration an influence on the compressor.
Thereby, it is possible to practice water injection while securing a safety operation of the gas turbine main body.
For example, when detecting means for detecting the temperature and humidity of gas at the upstream side of the compressor is provided, a water spray quantity limit value related to the temperature and humidity is set and the water quantity is controlled so that a real effective water spray quantity does not exceed the above-mentioned water spray quantity limit value during a water spraying operation, such cases can be considered that the effective water spray quantity is calculated from the humidity of gas at the compressor discharge portion and the humidity of gas at the upstream side of the injection unit and that it is calculated from a water quantity indication value of the water supply system and a drain occurrence amount in the intake air duct of the upstream side of the compressor. However, any case can be taken. The humidity of compressor discharge air can be measured by continuously drafting air into a tank for sampling which is provided with a humidity detecting means.
A second invention is a gas turbine, having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, and characterized by comprising an injection unit, arranged at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, a detection unit for detecting the opening of a compressor inlet vane, arranged in the compressor, and a controlling unit for controlling a quantity of water droplets to be sprayed from the injection unit on the basis of a signal from the detection unit.
For example, it is possible to set a limit value of a quantity of water droplets sprayed from the injection unit on the basis of the above-mentioned detection signal and control the spray quantity to be within the limit value. It is possible to set the above-mentioned limit value to be larger when the above-mentioned compressor vane opening is larger than when small. Since a quantity of air decreases according to a change in the guide vane angle or opening, a quantity of water is decreased as well.
Thereby, it is possible to inject a quantity of water corresponding to a quantity of air at the compressor inlet at the time of partial load operation. Further, it is possible to secure the soundness of the apparatus and devices of the plant at the time of partial load operation.
There are cases such that a quantity of air introduced into the compressor is decreased by throttling the guide vane of the compressor and that the quantity of air decreases because of a rise in atmospheric temperature, however according to the present construction, it is possible to inject a suitable quantity of water according to an increase or decrease in an intake air quantity at the time of a partial load operation. It is possible to suppress a condition such as an excessive amount of water spray, and operate the gas turbine at a high output while protecting the apparatus and devices.
Further, it is preferable to detect the above-mentioned compressor inlet guide vane angle and the compressor inlet air quantity and limit the spray quantity of water droplets according to the intake air quantity. In this case, it is further preferable to have determined the water droplet spray quantity according to ratios thereof to the compressor inlet air quantity because it is possible to influence, on the water droplet spray quantity, difference between individual machines of the same kind, a decrease in a compressor intake air quantity due to aged deterioration and a scale ratio in machine kinds of similar figures.
A third invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit for controlling the injection unit so as to stop injection of water droplets from the injection unit at time of starting of the gas turbine and start injection of water droplets from the injection unit after the gas turbine has come into a rated operation.
A shift of an operation of the gas turbine to a rated operation can be detected by a prescribed opening of the compressor inlet guide vane (an opening at time of normal operation, a full opening, etc.). Further, it can be detected by coming into an operation of a constant combustion temperature.
After the shift to the rated operation, for example, when a difference occurs between a required output value and a real output value, it is possible to operate by controlling the above-mentioned water droplet spray quantity so that the real output becomes a required output.
Thereby, it is possible to provide a gas turbine with a safe output increasing mechanism by water spray while protecting the gas turbine.
Even under the condition the gas turbine is operated at a constant partial load, it is possible to control so as to execute a water spray operation. Thereby, the thermal efficiency at the time of a partial load operation can be improved.
A fourth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into said compressor with the air having been lowered in temperature are evaporated during passage through the compressor, the injection unit having a plurality of spray nozzles for spraying water droplets, and a controlling unit for controlling the injection unit so that the number of the spraying nozzles spraying water droplets more than a prescribed quantity of water droplets becomes more than the number of the spraying nozzles spraying water droplets less than the prescribed quantity of water droplets.
For example, the above-mentioned injection unit has a water supply apparatus, a water supply main pipe line for supplying water from the water supply apparatus, a water supply header distributing water supplied from the water supply main pipe to a plurality of water supply pipes, and nozzles arranged on water supply pipes in which water distributed by the header flows for spraying the water droplets, and it can be further provided with a control unit which control so that the number of water supply pipes for supplying the water when the water droplet spray quantity is larger than a prescribed amount becomes more than the number of water supply pipes supplying the water when the water droplet spray quantity is smaller than the prescribed quantity.
Further, in the case where the above-mentioned spray nozzle is a two-fluid nozzle, the spray nozzle can be arranged so as to communicate with an air supply main pipe supplying air from the air supply apparatus, an air supply header distributing the air supplied from the air supply main pipe and air supply pipes in which air distributed by the header flows.
Further, for example, the construction of the above-mentioned water supply header of the injection unit can be constructed as follows:
The injection unit comprises a water supply apparatus, a water supply main pipe supplying water from the water supply apparatus, a main water supply header distributing water supplied from the water supply main pipe to a plurality of water supply branch pipes, an auxiliary water supply header distributing water flowing the water supply branch pipes to a plurality of water supply pipes, and nozzles, arranged on the water supply pipes in which water branched by the auxiliary water supply header flows, for spraying water droplets.
Thereby, even when the spray quantity of water droplets increases and decreases, it is possible to stably spray water droplets and an operation of high output can be carried out with the stable water spray.
Further, it is possible to suppress non-uniformity in the water quantity supplied to the spray nozzles, etc.
A fourth invention is characterized by providing a water supply flow regulation valve on an upstream side of the water supply header or water supply main header and controlling a water spray quantity by the water supply flow regulation valve. Thereby, water can be supplied simultaneously to the water spray nozzles at a fixed flow rate.
Further, with respect to a control of a flow rate, it is possible to provide a feed water flow regulation valve each between a downstream side of the feed water main header and the upstream side of the feed water auxiliary headers, and control a water spray quantity by the feed water flow regulation valve according to a required water spray quantity. It also is possible to control the water spray quantity by changing the number of the operating feed water auxiliary headers according to the water spray quantity. Further, it is possible to provide a feed water regulation valve between a downstream side of the feed water main header or feed water auxiliary header and an upstream side of the spray water piping and control a water spray quantity thereby. Further, it is possible to provide a feed water flow regulation valve between a downstream side of the spray water piping and an upstream side of the spray nozzles and control the water spray quantity from the spray nozzles thereby.
A fifth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, the injection unit having a water supply system, an air supply system and a spray nozzle for being supplied with water and air from the water supply system and air supply system and spraying water droplets, and a controlling unit for controlling the water supply quantity and air supply quantity so as to suppress variation between a ratio of water and air supplied to the spray nozzle when the water droplet supply quantity is small and a ratio of water and air supplied to the spray nozzle when the water droplet supply quantity is large.
In this manner, an air supply quantity is controlled according to a change in a water supply quantity so that a ratio of air and water becomes constant (so that variation in the ratio is suppressed) according to a water spray quantity.
Thereby, it is possible to obtain water droplets of prescribed diameter while keeping the air quantity small (it is preferable in a case where a water quantity is relatively small). In a case where air is taken from the compressor, it is possible to supply a larger amount of air from the taken air to the combustor, and an operation of high output or high efficiency can be carried out even if the water droplet spray quantity is changed.
A sixth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, the injection unit having a water supply system, an air supply system and a spray nozzle for being supplied with water from the water supply system and spraying water droplets, and a controlling unit for controlling the water supply quantity and air supply quantity as to increase a ratio of water to air, supplied to the spray nozzle when a spray quantity of water droplets is more, as compared with a small spray quantity.
Thereby, it is possible to obtain water droplets of a prescribed diameter while keeping the air quantity small (it is preferable when the water quantity is relatively small). In a case where air is taken from the compressor, it is possible to supply a larger amount of air from the taken air to the combustor, and an operation of high output or high efficiency can be carried out even if the water droplet spray quantity changes.
A seventh invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, said injection unit having a water supply system, an air supply system and a spray nozzle for being supplied with water and air from the water supply system and air supply system and spraying water droplets, and a controlling unit for controlling the water supply quantity and air supply quantity so as to increase and decrease the water supply quantity according to an increase and a decrease of a spray quantity of water droplets and maintain the air supply quantity to be constant.
Thereby, it is possible to execute a high output operation by water spray while keeping the soundness of the apparatus and devices, with a simple control.
An eighth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, and characterized by comprising an injection unit, arranged at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, the injection unit having a water supply system, an air supply system and a spray nozzle for being supplied with water and air from the water supply system and air supply system and spraying water droplets, and a controlling unit for controlling the injection unit so as to start supplying of air to the spray nozzle first and then start to supplying of water to the spray nozzle, thereby to start spraying of water droplets.
A ninth invention is a gas turbine, having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, and characterized by comprising an injection unit, arranged at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, the injection unit having a water supply system, an air supply system and a spray nozzle for being supplied with water and air from the water supply system and air supply system and spraying water droplets, and a controlling unit for controlling the injection unit so that the water droplet spraying is stopped by decreasing a quantity of air supplied to the spray nozzle first and then decreasing a quantity of water supplied to the spray nozzle.
Thereby, it is possible to secure the soundness of the apparatus and devices at a time of starting the water spray operation or at a time of stopping the water spray operation, and it is possible to provide a gas turbine which outputs a high output by the water spray operation. Further, it is possible to suppress occurrence of water droplets having an undesired diameter at the time of starting and stopping.
A tenth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, and characterized by comprising an injection unit, arranged at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit for controlling the injection unit so as to first issue a signal for stopping the water droplet spraying and then issue an instruction to decrease the compressor inlet guide vane opening on the basis of a gas turbine trip signal, during operation of the injection unit.
Thereby, a high output can be obtained by the water spray operation, and even if a gas turbine trip occurs during the water spray operation, it is possible to provide a gas turbine of a high safety which can effect a smooth trip, securing the soundness of the apparatus and devices.
An eleventh invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit, having a plurality of air temperature detectors arranged in the duct on a peripheral direction, for controlling the injection unit so as to decrease a quantity of water spray when a deviation in detected value reaches to a prescribed value, during an operation of spraying water droplets.
Further, it is possible to control the water spray quantity so as to decrease when the a set temperature set by taking account of icing and so on exceeds a prescribed value. When the water spray quantity is decreased, it is possible to control so as to increase, according to a detection value, a flow rate of water flowing in a spray nozzle portion corresponding to a position in which a detection value changes largely by a prescribed value form an average value of the other detection values, or it is possible to decrease the water spray quantity of the whole spray nozzles.
A twelfth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit for controlling the injection unit so as to monitor a flow rate by weight of air introduced into the compressor and decrease a quantity of water spray when the flow rate reaches to a prescribed value, during operation of spraying water droplets.
Thereby, since the change can be directly monitored, stall and icing can be precisely suppressed, whereby a gas turbine which can carry out a high output operation by water spray can be provided while keeping the soundness of the apparatus and devices.
In a case where a device for measuring an air quantity at the compressor inlet is provided and a water quantity is controlled relative to the air quantity at the compressor inlet during the water spray operation, any of the operations can be effected in one of which one arbitrary constant value is set in advance as an allowable variation range and the water quantity is decrease not to exceed the allowable variation range, in the other of which water supply is stopped when the water quantity exceeds the allowable variation range. In a case of stopping of water supply, any methods can be taken one of which is a method of stopping water supply by an operation of the feed water stopping valve of the water supply system when it exceeds the allowable variation range and other is a method of stopping the water supply by stopping the feed water pump of the water supply system.
Further, this control unit is preferable to be applied in the case where such a water spray quantity is injected that some of the quantity thereof has not been evaporated and remains as water droplets in the intake duct and the quantity of the not-evaporated liquid droplets are introduced into the compressor.
For example, the above-mentioned detection is executed at an interval of several minutes (for example, 2 to 3 minutes), and it is possible to judge after monitoring at the detection interval.
Since an air quantity decreases as the atmospheric temperature rises, in order to distinguish it from an decrease of the air quantity due to stall, it is preferable to calculate an air quantity change by detecting the air temperature.
Further, the air temperature is preferable to be detected at a compressor inlet portion (for example, between a downstream side of the injection unit and the compressor inlet).
It is possible to replace the detection of an inlet air flow rate by detection of a compressor discharge pressure by providing a detection device detecting a compressor discharge pressure on a compressor discharge air flow passage.
Alternatively, it is possible to provide means for detecting a gas turbine intake air temperature and a control unit controlling so as to injection water spray when the air temperature becomes a constant value or more. At this time, although a gas temperature at an upstream side of the injection unit and a gas temperature at a downstream side of the injection unit are considered as a gas temperature to be detected for the control, any gas temperature can be used. In a case where it is detected at the downstream side of the injection unit, it is possible to detect the air temperature at a plurality of points in the same plane in a flow direction. When the air temperature lowers than a lower limit value, a water spray injection quantity is limited according to the air temperature. Otherwise, it is possible to stop the water supply.
Thereby, a stable operation of the gas turbine can be achieved while avoiding an icing phenomenon on the compressor inlet guide vanes.
Further, by providing means for detecting the temperature and humidity of a gas turbine intake air and a calculator for calculating a wet-bulb potential temperature from the humidity, or providing means for detecting an air wet-bulb potential temperature, it is possible to provide a control unit controlling so as to inject water spray when the wet-bulb potential temperature is a constant value or more. In this case, although a wet-bulb potential temperature at a upstream side of the injection unit and a wet-bulb potential temperature at a downstream side of the injection unit are considered as a wet-bulb potential temperature used for the control, any of which can be used. In a case where the wet-bulb potential temperature lowers than a lower limit value, the water spray injection quantity can be limited according to the temperature or it is possible to stop the water supply.
Thereby, a stable operation of the gas turbine can be achieved while avoiding an icing phenomenon on the compressor inlet guide vanes.
A thirteenth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, a detection unit for detecting the pressure of a casing wall of an inlet guide vane portion of the compressor, and a controlling unit for controlling a quantity of water spray on the basis of the detected wall pressure, during an operation of water droplet injection.
For example, the above-mentioned control unit monitors the casing wall pressure at a compressor inlet guide vane inlet and controls so as to decrease the water spray quantity when the flow rate becomes a prescribed value or more, during the water spray operation
Thereby, it is possible to monitor the casing pressure of the compressor inlet guide vane inlet and approximate an air flow rate change thereby, whereby it is possible to easily detect a condition change, and make the output high by the water spray injection while easily securing the soundness of the apparatus and devices.
Further, other than it, it is possible to detect the pressure inside the compressor and control so as to decrease the water injection quantity on the basis of rising in the pressure more than a prescribed value. Thereby, the detecting device is easily installed and the air quantity can be easily detected.
Further, it is possible to detect a change in pressure inside the compressor and to control so as to decrease the water spray quantity when the pressure change becomes larger than a prescribed value. Thereby, it is possible to directly measure an abnormal condition and detect precisely the event.
A fourteenth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit f or controlling the injection unit so as to monitor a discharge pressure of the compressor and decrease a quantity of water spray when the discharge pressure becomes less a prescribed value, during an operation of spraying water droplets.
For example, the above-mentioned control unit monitors a compressor discharge pressure and control so as to the water spray quantity when the discharge pressure becomes less than a prescribed value, during a water spray injection operation. Thereby, it is possible to rapidly detect an abnormal condition which is high in pressure level, such as icing, stall, etc. Therefore, it is possible to effect a high output operation by the water spray injection and detect early occurrence of icing, stall, etc. and maintain the soundness of the apparatus and devices.
When a means for detecting a compressor discharge pressure is provided and a water injection quantity is controlled according to the compressor discharge pressure during the water spray injection operation, a constant value is set in advance as an allowable variation range and it is possible to operate so as to decrease not to exceed the allowable variation range or to operate so as to stop the water supply when it exceed the allowable variation range.
A fifteenth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit for monitoring an adiabatic efficiency of the compressor and controlling a quantity of water spray on the basis of the adiabatic efficiency, during an operation of water droplet injection.
For example, the above-mentioned control unit monitors a compressor adiabatic efficiency and controls so as to decrease the water spray quantity when the adiabatic efficiency lowers less than a Prescribed value, during the water spray injection operation.
Thereby, even if an atmospheric temperature changes, the temperature can be detected, and an icing, stall, etc. can be detected. Therefore, even if the atmospheric temperature changes, it is possible to easily protect the apparatus and devices from the icing, stall, etc. and to provide a gas turbine of high output by the water spray injection. Further, mismatching between stages inside the compressor can be detected, a further safe operation can be effected.
When a means for measuring a compressor adiabatic efficiency is provided and a water quantity is controlled according to the compressor adiabatic efficiency during the water spray injection operation, a constant value is set in advance as an allowable variation range, and any of an operation in which the water quantity is decreased not to exceed the allowable variation range and an operation in which the water supply is stopped when it exceeds the allowable variation range can be practiced.
A sixteenth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through said compressor, and a controlling unit for monitoring an exhaust gas temperature and controlling a quantity of water spray on the basis of the exhaust gas temperature, during an operation of water droplet injection.
For example, the above-mentioned control unit monitors an exhaust gas temperature and control so as to decrease the spray water quantity when the exhaust gas temperature becomes a prescribed value or more, during the water spray injection operation.
Thereby, it is possible to rapidly detect a change in event and suitably protect the apparatus and devices from an abnormal condition, and achieve a high output operation of the gas turbine by the water spray injection.
By providing a means for detecting a combustion exhaust gas temperature, when the water quantity is controlled according to the combustion exhaust gas temperature during the water spray injection operation, a constant value is set in advance as an allowable variation range and any of an operation in which the water quantity is decreased not to exceed the allowable variation range and an operation in which the water supply is stopped when it exceeds the allowable variation range, can be effected.
A seventeenth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit for monitoring vibrations of a gas turbine bearing and controlling a quantity of water spray on the basis of the vibration value, during an operation of water droplet injection.
For example, the above-mentioned control unit monitors vibrations of a gas turbine bearing and controls so as to decrease the water spray quantity when the vibrations exceeds a prescribed value, during the water spray injection operation.
Thereby, it can be directly detected that stool occurs partially in a peripheral direction, and partial stall and icing can be directly detected. It is possible to protect the apparatus and devices from abnormality by detection of partial stall and icing, and provide a high output operation of gas turbine by the water spray injection. Further, it is possible to detect suitably vibrations due to unbalance of a gas turbine rotating portion, caused by ununiformity in water droplets introduced in the compressor and carry out a high safety operation.
In a case where by providing a means for detecting vibrations of the gas turbine bearing, and the water injection quantity is controlled according to the vibrations of the bearing during the water spray injection operation, a constant value is set in advance as an allowable variation range, it is possible to effect an operation that the water quantity is decreased not to exceed the allowable variation range or an operation that the water supply is stopped when it exceeds the allowable variation range.
An eighteenth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit for monitoring a thrust bearing metal temperature of the gas turbine and controlling a quantity of water spray injection on the basis of the thrust bearing metal temperature, during an operation of water droplet injection.
For example, the above-mentioned control unit monitors a metal temperature of a gas turbine thrust bearing and controls so as to decrease the water spray quantity when the metal temperature exceeds a prescribed value, during the water spray injection operation.
Thereby, a temperature change in the thrust bearing can be detected and if an unbalance in the thrust bearing occurs, it can be surely detected. It is possible to protect the apparatus and devices from abnormality caused by the unbalance, and provide a high output operation of gas turbine by the water spray injection.
In a case where by providing a means for detecting a metal temperature of the gas turbine thrust bearing, and the water quantity is controlled according to the metal temperature of the thrust bearing during the water spray injection operation, a constant value is set in advance as an allowable variation range, it is possible to effect an operation that the water quantity is decreased not to exceed the allowable variation range or an operation that the water supply is stopped when it exceeds the allowable variation range.
A nineteenth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit for monitoring an axial flow velocity of fluid flowing in the compressor and controlling a quantity of water spray on the basis of the axial flow velocity, during an operation of water droplet injection.
For example, the above-mentioned control unit monitors an axial flow velocity of fluid inside the compressor and controls so as to decrease the water spray quantity when the axial flow velocity lowered to a prescribed value or less, during the water spray injection operation. Since it is determined irrespective of such conditions as atmospheric temperature, etc., the control can be easily carried out and a precise control can be effected with respect to this point. Further, it is possible to determine a limit value of a water spray quantity on the basis of this value and make it a control ground, whereby direct control can be effected.
Thereby, it is possible to protect the apparatus and devices from abnormality caused by an icing and so on and provide a high output operation of gas turbine by the water spray injection.
In a case where by providing a means for calculating an axial flow velocity inside the compressor, and the water quantity is controlled according to the axial flow velocity of fluid in the compressor during the water spray injection operation, although the axial flow velocity can be considered to be calculated at any stage, it is possible to calculate an axial flow velocity at the final stage of the a compressor from an air quantity at the compressor inlet, a compressor discharge pressure and a compressor discharge temperature. An operation method in which a constant value is set in advance as an allowable variation range, and the water quantity is decreased not to exceed the allowable variation range and an operation that the water supply injection is stopped when it exceeds the allowable variation range are considered, however, any of the operations can be used. Further, when the water supply is stopped, although there are a method of stopping water supply by an operation of feed water shut-off valve of a feed water system and a method of stopping water supply by stopping a feed water pump, any of the methods can be used.
Alternatively, it is possible to provide a means for detecting a drain quantity in the compressor inlet air intake portion and a control unit controlling the water quantity according to the drain quantity. An operation method in which an arbitrary constant value is set in advance as an allowable variation range, and the water quantity is decreased not to exceed the allowable variation range and an operation method in which the water supply is stopped when it exceeds the allowable variation range are considered, however, any of the operation methods can be used. The drain quantity can be detected by arranging a high level switch in the drain tank.
When the water supply is stopped, although there are a method of stopping water supply by an operation of feed water shut-off valve of a feed water system and a method and an operation method of stopping water supply by stopping the feed water pump of the feed water system, any of the methods can be used.
Thereby, since the compressor is made not to suck water droplets of large diameter, it is possible to carry out a stable operation of the compressor and gas turbine and to avoid wear of the compressor blades.
A twentieth invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through said compressor, and a controlling unit for controlling said injection unit so as to increase a quantity of fuel supplied to the combustor at time of water droplet spraying, as compared with a quantity of fuel supplied to the combustor at time of stopping water droplet spraying.
Further, it is preferable to have a control unit controlling so as to increase a fuel supply quantity supplied to the combustor more than before the water spray injection starting on the basis of the water spray injection starting and decrease the fuel supply quantity less than before the water spray injection stopping on the basis of the water spray injection stopping.
Further, at the time of water spray injection also, it is preferable to provide a control unit controlling so as to increase a fuel injection amount to the combustor more when the water droplet spray injection quantity is more, than when the water spray injection quantity is small.
Further, it is preferable to control (correct or compensate) the fuel supply quantity according to the humidity.
In a case where a gas turbine exhaust gas temperature is used to control a gas turbine inlet temperature constant, a method of correcting a value detected of the gas turbine exhaust gas temperature according to the humidity quantity at the gas turbine inlet and a method of correcting a predetermined exhaust gas temperature control line according to the humidity quantity at the gas turbine inlet are considered.
Concretely, for example, it is possible to increase a fuel injection amount by correcting the exhaust gas temperature control line set based on water droplet spray not practiced toward a high temperature side during the water spray injection operation.
Alternatively, it is possible to increase the fuel injection amount by correcting a measure value of exhaust gas temperature.
In a case where detection of the humidity around the compressor is practiced at an upstream side of the compressor, a method of calculating it from the humidity of gas at the upstream side of the injection unit, water spray injection quantity from the injection unit and a drain amount occurred in the intake air duct can be considered. The detection of humidity can be practiced at the compressor discharge portion.
Thereby, an operation of the gas turbine that always keep the combustion temperature constant without influence of the water spray infection is possible and it is possible to achieve an output improving effect by water spray injection to the maximum.
Thereby, the combustion temperature is suitably corrected (for example, corrected to a higher temperature side) and a further improvement on output can be achieved during the water spray injection operation.
A twenty-first invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, a detection unit for detecting NOx concentration in the exhaust gas, and a controlling unit for controlling a quantity of water spray on the basis of the detected NOx concentration.
As compared with NOx countermeasures by water or steam spraying into the combustor, a mixing condition of water and air is better because a gas that air and water in the combustor are mixed homogeneously flows in the combustor. Therefore, it is possible realize a low NOx emission while suppressing combustion vibrations and effecting stable combustion, with a simple apparatus.
Based on a value detected of NOx concentration of gas turbine exhaust gas, a water quantity is controlled according to difference between a target NOx concentration and the above-mentioned gas turbine exhaust gas NOx concentration value, whereby it is possible to decrease the NOx concentration to the target value.
A twenty-second invention is a gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from the compressor and a fuel and a gas turbine to be driven by a combustion gas from the combustor, characterized by comprising a premixer provided in the combustor for burning premixed gas formed by premixing fuel and air an injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that k water droplets are sprayed into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor to a temperature lower than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having been lowered in temperature are evaporated during passage through the compressor, and a controlling unit for monitoring an adiabatic efficiency of the compressor and controlling a quantity of water spray on the basis of the adiabatic efficiency, during an operation of water droplet injection.
Further, it is preferable to control so that a ratio of fuel to air in a premixed gas becomes higher when the water spray quantity is more.
A variation in water spray quantities changes greatly a condition of fluid. However, it is possible to suppress the combustion condition becoming unstable during the water spray injection operation by the invention. Therefore, it is possible to provide a gas turbine which has a high stability of combustion and is able to carry out a high output operation by water spray injection.
Further, in stead of the above-mentioned control unit, it is possible to provide a NOx concentration detection device for detecting a NOx concentration of the combustion exhaust gas, a pressure variation detection device for detecting pressure variation inside the combustor, and a control unit controlling so as to increase the above-mentioned water droplet spray quantity when the NOx concentration reaches to a prescribed value or more, and decrease the water droplet spray quantity when the pressure variation becomes a prescribed value or more.
Thereby, an operation that an output is made higher by the water spray injection, an emitted NOx concentration is lower and a combustion stability is higher.
Further, by providing a means for detecting the NOx concentration of gas turbine exhaust gas and the pressure variation in the combustor, it is possible to control the water spray quantity at the upstream side of the compressor so as to suppress the gas turbine exhaust gas NOx concentration and the pressure variation in the combustor within allowable values.
Further, in a case where steam or water is injected into the combustor, also, in the similar manner, it is possible to control the water injection quantity at the upstream side of the compressor and the water or steam injection quantity to the combustor so that the gas turbine exhaust gas NOx concentration and the combustor inside pressure variation during an operation of the water spray injection at the upstream side of the compressor each become within an allowable value. Thereby, it is possible to achieve a stable operation of the combustor.
Further, by providing a means for monitoring the gas turbine exhaust gas NOx concentration and the combustor inside pressure variation, it is possible to control a premixed combustion ratio so that the gas turbine exhaust gas NOx concentration and the combustor inside pressure variation each do not exceed a constant value set in advance during the water spray injection operation. Thereby, it is possible to achieve a stable operation of the combustor.
With respect to the gas turbine explained above, it is possible to make higher output of gas turbines already made and installed in addition to gas turbines newly installed. In this case, the already made gas turbines each are provided with the above-mentioned injection unit, any of the above-mentioned control units according to an object or demand, related apparatus and devices if necessary, as a gas turbine output augmenting system.
In this manner, the above-mentioned operation of each of the inventions can be achieved by providing the above-mentioned injection unit, control unit, or, further necessary related apparatus and devices even in already made gas turbines.
Further, if it is accepted that there may be some cases wherein the above-mentioned operation and effect are not sufficiently presented, instead of the above-mentioned injection unit, arranged within an intake air duct at an upstream side of the compressor and constructed so that water droplets are injected into the air to be supplied to the compressor to lower the temperature of the air to be supplied into the compressor than an atmospheric temperature and the sprayed water droplets introduced into the compressor with the air having lowered in temperature are evaporated during passage through the compressor, or in addition to the above-mentioned injection unit, the above-mentioned control unit can be employed for a system or apparatus provided with a cooling device for cooling air supplied to the compressor to increase output. The cooling device can be a device for effecting direct or indirect heat exchange with air supplied to the injection unit and the compressor, using a cold heat source such as ice, liquid air, etc.